CHICAGO -- A good Samaritan was shot and killed after chasing down the driver who hit a biker and fled the scene.

The incident happened around 1:30 a.m. at 76th and Champlain in the city's Chatham neighborhood.

Police said Albert Bocanegra, 39, was in a car recording a group of bike riders, when a 30-year-old female rider was struck by a vehicle. The driver fled the scene.

Police said Bocanegra chased down the offender's vehicle and confronted the driver. The two got into a verbal altercation, when another vehicle approached and someone inside fired shots, striking the man twice in the neck.

Bocanegra was transported to the University of Chicago Hospital where he later died.

Bocanegra was a community activist in Brighton Park and former aldermanic candidate. He was reportedly battling cancer.

Last year, Bocanegra was arrested and charged with a felony for allegedly firing off his weapon in the South Loop in what appeared to have been a road rage incident. B

No one is in custody as Area South detectives investigate. A $2000 reward is being offered for information leading to the shooter.

The woman who was hit by the car is in good condition with a shoulder injury.